*{
    /*初始化*/
    margin:0;
    padding: 0;
    box-sizing: border-box;
}
body{
    /*弹性布局 居中显示*/
    height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    background: linear-gradient(to top left,#ffe29f,#ffa99f,#ff719a);
    overflow: hidden;
}
.container{
    text-align: center;
    color: white;
}
.container h1{
    font-size: 40px;
    font-weight: 100;
    letter-spacing:2px ;
    margin-bottom: 15px;
    transition: 1s ease-in-out;
}
.form{
    display: flex;
    flex-direction: column;
    align-items: center;
    /*sticky定位*/
    position: relative;
    z-index: 2;
    opacity: 1;
    /*不透明度改变时的过渡效果*/
    transition: opacity 0.5s;
}
.form input{
    outline: none;
    border: 1px solid rgba(255,255,255,0.4);
    background-color: rgba(255,255,255,0.2);
    width:250px;
    padding: 10px 15px;
    border-radius: 3px;
    margin: 0 auto 10px auto;
    text-align: center;
    color: white;
    font-size: 15px;
    transition: 0.25s;
}
.form input::placeholder{
    color: white;
    font-size: 14px;
    font-weight: 300;
}
.form input:hover{
    background-color: rgba(255,255,255,0.4);
}
.form input:focus{
    background-color: white;
    width: 300px;
    color: #ff719a;
}
.btn-login{
    outline: none;
    background-color: white;
    color: #ff719a;
    border: none;
    width: 250px;
    padding: 10px 15px;
    border-radius: 3px;
    font-size: 15px;
    cursor: pointer;
    transition: 0.25s;
}
.btn-login:hover{
    background-color: #f5f7f9;
}
/*背景方块*/
.bg-squares{
    list-style: none;
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 1;
}
.bg-squares li{
    width: 40px;
    height: 40px;
    background-color:rgba(255,255,255,0.15);
    position: absolute;
    /*到底下去了*/
    bottom: -160px;
    /*动画 持续时间 线性 无限次播放*/
    animation:  2s square linear infinite;
}
/*为每一个放个设置不同的位置大小动画*/
.bg-squares li:nth-child(1){
    left:10%;
}
.bg-squares li:nth-child(2){
    left:20%;
    width: 80px;
    height: 80px;
    /*动画延迟时间，会延迟2s出来*/
    animation-delay: 2s;
    /*动画周期时长*/
    animation-duration: 17s;
}
.bg-squares li:nth-child(3){
    left:25%;
    animation-delay: 4s;
}
.bg-squares li:nth-child(4){
    left:40%;
    width: 60px;
    height: 60px;
    background-color: rgba(255,255,255,0.4);
    animation-duration: 22s;
}
.bg-squares li:nth-child(5){
   left: 70%;
}
.bg-squares li:nth-child(6){
    left:80%;
    width: 120px;
    height: 120px;
    background-color: rgba(255,255,255,0.2);
    animation-delay: 3s;
}
.bg-squares li:nth-child(7){
    left:32%;
    width: 160px;
    height: 160px;
    animation-delay: 7s;
}
.bg-squares li:nth-child(8){
    left:55%;
    width: 20px;
    height: 20px;
    animation-delay: 15s;
    animation-duration: 40s;
}
.bg-squares li:nth-child(9){
    left:25%;
    width: 10px;
    height: 10px;
    background-color: rgba(255,255,255,0.3);
    animation-delay: 2s;
    animation-duration: 40s;
}
.bg-squares li:nth-child(10){
    left:90%;
    width: 160px;
    height: 160px;
    animation-delay: 11s;
}
.container.success h1{
    transform: translateY(75px);
}
.container.success .form{
    opacity: 0;
}
@keyframes square {
    0%{
        transform: translateY(0);
    }
    /*沿Y轴移动并且旋转*/
    100%{
        transform: translateY(-120vh) rotate(600deg);
    }
}

